66 THE BUTTERFLY VIVARIUM. 



were encased in the six pectoral legs of the Cater- 

 pillar. The skin and other external portions of the 

 Caterpillar are therefore little more than a kind of 

 shell, and the Caterpillar, in fact, a " walking egg." 

 It is also a walking egg which has the still 

 more unusual faculty of eating ; not merely taking 

 in nourishment by absorption, as some eggs are 

 known to do, but by means of a positive mouth and 

 mandibles of a formidable description; which, in 

 the case of the Caterpillars of Butterflies, form a 

 striking contrast with the delicate feeding-trunk 

 of the perfect creature. But it is time to consider 

 Caterpillars of various kinds in some detail, and 

 with reference to the form and structure of their 

 various members, as well as the different functions 

 of those members, which will, with the instincts of 

 their possessors, afford opportunities for much 

 curious and interesting observation. 



In these investigations the general term larva 

 will be more convenient than that of Caterpillar, as 

 applying to the second stage of all classes of insects, 

 especially as that popular term is, as I have stated 

 before, generally confined to the larva3 of Butterflies 

 and Moths. The popular name, " Grubs," by which 

 the larvse of the Beetle section of the insect family are 

 distinguished, is exceedingly expressive of their mode 



